LANCE ARMSTRONG says he "deserves" to compete again and will fight his lifetime ban from sport, saying that he has received the "death penalty" while other cheats have got off lightly.

Breaking down in the second part of a televised interview with Oprah Winfrey, the self-confessed liar, bully and narcissist accepted he should be punished for doping throughout his seven Tour de France victories, but not as harshly as he has been.

The US Anti-Doping Agency stripped Armstrong of his titles and banned the one-time hero from sanctioned sporting events for life in October.

In what was billed as a tell-all confessional, Armstrong did not give information about who supported his doping, who he doped with, and who helped cover it up.

After the first part of the interview, televised on Friday, the head of cycling's besieged world governing body, Pat McQuaid, trumpeted that Armstrong had proved there was "no collusion or conspiracy" between the International Cycling Union (UCI) and the American cyclist.

McQuaid based that statement on Armstrong's emphatic denial that he donated six-figure sums to the UCI to cover up positive doping tests.

Armstrong lamented he was banned from entering sporting events such as the Chicago marathon.

"I got a death penalty and they got six months," he said, comparing himself with riders who had given evidence about him to USADA and incurred a lighter sanction in return.

Armstrong went on to say that nothing was as bad as receiving a cancer diagnosis.

Anti-doping and sports officials have been scathing about the lack of detail he has shared.

International Olympic Committee member Dick Pound is suspicious about Armstrong's motives.

"If he's going to sell the fact that he's contrite ... he's going to have to do some more rehearsals," he said.